When someone is "marooned", he is cut off from the civilization with no means of returning home. In the XVII century the word "maroon" was first applied to runaway Negroslaves who, being fugitives, made their new homes in places as inaccessible as possible.

If you are "sold down the river" you get a bad deal. This phrase comes from the practice of Americansugarcaneplantation owners of getting rid of troublesome slaves by selling them to other landowners lower down the Mississippi.

It is often forgotten that some children were seized in England and sold to plantation owners to work as servants in America. Thus, the word "kidnap" is composed of kid (boy) plus nap (steal).

It is not longer used the word "petard" except in the phrase "hoist with his own petard", the sad fate of that man lighting the fuse.

The expression "when balloon goes up" indicates that events are becoming critical. In both World Wars barrage balloons were used to deter low-flying enemy aircrafts. If a balloon was sent up, it meant that air attack must be imminent.

I’ve been interested in idioms ever since I overheard my primary schoolteacher telling her colleague that she was fed up because “the kids in the class are always berwi fel caws pys”. I knew of course that this meant the children were ‘boiling like pea soup’, but I had no idea what it meant. Only later did I discover that she was annoyed that the class wouldn’t stop talking.

It was then that I realised that every language must have its own idioms, and that they probably make exactly as little sense to foreign learners as our own:

Shortly before I moved to Germany, I received a book of German idioms from a colleague as a leaving present. It was quite old, but provided an interesting insight into the German mindset, for example, the German equivalent to ‘all good things must come to an end’ is „alles hat ein Ende - nur die Wurst hat zwei“ (lit: ‘everything has an end, only the sausage has two’ - It’s hard to imagine any race stereotyping itself more effectively!).

Aside from confirming what we always knew about Germans and their eating habits, the book was sadly a bit dull. It was technically a dictionary which listed an idiom followed by a short explanation, for example:

which whilst useful, isn’t really interesting. For my 23rd birthday however, I received a fantastic French idiom dictionary called «Nom d’une Pipe!» which was not only fully illustrated with Blake and Mortimer comics, but also contained literal, word-for-word translations into English:

Idioms are what make languages interesting. They not only give an fascinating insight into the people (such as confirming that Germans eat only sausages or that the French are prone to licking bears, though sometimes not very well) but they also give the language itself a new depth and richness. Sure, ‘he ran away’ works, but ‘he legged it’ is far more descriptive.

As I’ve mentioned, the “big” languages have not only idiom dictionaries but also books about them, analysing them and generally making them interesting. Sadly however, smaller languages do not. Welsh, for example, has only three books of idioms, all of which were written before 1979. And useful though they are, they’re very boring.

Another problem with smaller languages is that, when the native idiom gets forgotten, it often gets replaced with a translation of that of a more dominant language - in the case of Welsh, the English. For example, the perfectly good ‘dw i'n yfed cwrw ond unwaith yn y pedwar amser’ (lit: I drink beer only once in the four seasons) has been all but replaced with the English ‘unwaith yn y leuad glas’ - once in a blue moon.

This is a shame, as the father of the Welsh Nationalist movement, Emrys ap Iwan, so eloquently put it: “As shall be the language, so shall be the man, and so shall be the nation. Good language promotes civilisation, and poor language, or language that is not used well, hinders it.”

So to prevent the richness and interestingness of Welsh idiomatic speech dying out, I present you with 10 of my favourite Welsh idioms:

The syntactical or structural form peculiar to any language; the genius or cast of a language.

Idiom may be employed loosely and figuratively as a synonym of language or dialect, but in its proper sense it signifies the totality of the general rules of construction which characterize the syntax of a particular language and distinguish it from other tongues.
G. P. Marsh.

By idiom is meant the use of words which is peculiar to a particular language.
J. H. Newman.

He followed their language [the Latin], but did not comply with the idiom of ours.
Dryden.

2.

An expression conforming or appropriate to the peculiar structural form of a language; in extend use, an expression sanctioned by usage, having a sense peculiar to itself and not agreeing with the logical sense of its structural form; also, the phrase forms peculiar to a particular author.

Some that with care true eloquence shall teach,
And to just idioms fix our doubtful speech.
Prior.

Sometimes we identify the words with the object -- though be courtesy of idiom rather than in strict propriety of language.
Coleridge.

Every good writer has much idiom.
Landor.

It is not by means of rules that such idioms as the following are made current: "I can make nothing of it." "He treats his subject home." Dryden. "It is that within us that makes for righteousness." M.Arnold.
Gostwick (Eng. Gram. )

3.

Dialect; a variant form of a language.

Syn. -- Dialect. -- Idiom, Dialect. The idioms of a language belong to its very structure; its dialects are varieties of expression ingrafted upon it in different localities or by different professions. Each county of England has some peculiarities of dialect, and so have most of the professions, while the great idioms of the language are everywhere the same. See Language.